New Diagnostic Approach for Esophageal Squamous Cell Neoplasms Using Linked Color Imaging and Blue Laser Imaging Combined with Iodine Staining

Linked color imaging vs Lugol chromoendoscopy for esophageal squamous cell cancer and precancerous lesion screening: A noninferiority study

BACKGROUND

Lugol chromoendoscopy (LCE) has served as a standard screening technique in high-risk patients with esophageal cancer. Nevertheless, LCE is not suitable for general population screening given its side effects. Linked color imaging (LCI) is a novel image-enhanced endoscopic technique that can distinguish subtle diff-erences in mucosal color.

AIM

To compare the diagnostic performance of LCI with LCE in detecting esophageal squamous cell cancer and precancerous lesions and to evaluate whether LCE can be replaced by LCI in detecting esophageal neoplastic lesions.

METHODS

In this prospective study, we enrolled 543 patients who underwent white light imaging (WLI), LCI and LCE successively. We compared the sensitivity and specificity of LCI and LCE in the detection of esophageal neoplastic lesions. Clinicopathological features and color analysis of lesions were assessed.

RESULTS

In total, 43 patients (45 neoplastic lesions) were analyzed. Among them, 36 patients (38 neoplastic lesions) were diagnosed with LCI, and 39 patients (41 neoplastic lesions) were diagnosed with LCE. The sensitivity of LCI was similar to that of LCE (83.7% vs 90.7%, P = 0.520), whereas the specificity of LCI was greater than that of LCE (92.4% vs 87.0%, P = 0.007). The LCI procedure time in the esophageal examination was significantly shorter than that of LCE [42 (34, 50) s vs 160 (130, 189) s, P < 0.001]. The color difference between the lesion and surrounding mucosa in LCI was significantly greater than that observed with WLI. However, the color difference in LCI was similar in different pathological types of esophageal squamous cell cancer.

CONCLUSION

LCI offers greater specificity than LCE in the detection of esophageal squamous cell cancer and precancerous lesions, and LCI represents a promising screening strategy for general populations.

Inter-observer variability of experts and trainees for the diagnosis of reflux esophagitis: Comparison of linked color imaging, blue laser imaging, and white light imaging

OBJECTIVES

Diagnosis of reflux esophagitis according to the Los Angeles classification minimal change (LA-M) has a low inter-observer agreement. We aimed to investigate whether the inter-observer agreement of reflux esophagitis was better when expert endoscopists read the endoscopic images, or when the linked color imaging (LCI) or blue laser imaging (BLI)-bright mode was used. In addition, whether the inclusion of LA-M in the definition of reflux esophagitis affected the consistency of the diagnosis was investigated.

METHODS

During upper endoscopy, endoscopic images of the gastroesophageal junction were taken using white light imaging (WLI), BLI-bright, and LCI modes. Four expert endoscopists and four trainees reviewed the images to diagnose reflux esophagitis according to the modified LA classification.

RESULTS

The kappa values for the inter-observer variability for the diagnosis of reflux esophagitis were poor to fair among the experts (κ =  0.22, 0.17, and 0.27 for WLI, BLI-bright, and LCI, respectively) and poor among the trainees (κ =  0.18, 0.08, and 0.14 for WLI, BLI-bright, and LCI). The inter-observer variabilities for the diagnosis of reflux esophagitis excluding LA-M were fair to moderate (κ =  0.42, 0.35, and 0.42 for WLI, BLI-bright, and LCI) among the expert endoscopists and moderate among the trainees (κ = 0.48, 0.43, and 0.51 for WLI, BLI-bright, and LCI).

CONCLUSIONS

The inter-observer agreement for the diagnosis of reflux esophagitis was very low for both the expert endoscopists and the trainees, even using BLI-bright or LCI mode. However, when reflux esophagitis LA-M was excluded from the diagnosis of esophagitis, the degree of inter-observer agreement increased.

Usefulness of linked color imaging in the early detection of superficial esophageal squamous cell carcinomas

BACKGROUND AND AIMS

Linked color imaging (LCI) improved the visibility of gastric cancer and colorectal flat lesions. This study aimed to investigate the usefulness of LCI in detecting superficial esophageal squamous cell carcinomas (SESCC).

METHODS

We enrolled 37 consecutive SESCC patients (46 SESCCs) diagnosed using LCI and blue laser imaging bright mode (BLI-BRT) and treated in Hiroshima University Hospital between April 2018 and November 2018. Eight professional endoscopists compared images obtained on non-magnifying BLI-BRT and LCI versus conventional white light imaging (WLI). Identification and boundary diagnosis of SESCC with LCI and BLI-BRT were compared with WLI. Changes in lesion visibility were clarified. Interobserver agreement was assessed. Clinicopathological features of lesion that influence visibility with LCI were assessed.

RESULTS

In LCI, 37% (17/46) of cases had improved visibility and 63% (29/46) had unchanged visibility (interobserver agreement = 0.74). Among cases with multiple lugol voiding lesions (LVLs), ΔE between the lesion and background mucosa was significantly higher in LCI than in WLI (20.8 ± 7.9 vs 9.2 ± 6.1, P < 0.05). No significant differences were found in tumor size, morphological type, color, depth, and smoking or drinking history. However, multiple LVLs were significantly higher among cases with improved versus unchanged visibility. On BLI-BRT, 39% (18/46) of cases had improved visibility and 61% (28/46) had unchanged visibility (interobserver agreement = 0.60).

CONCLUSION

Almost the same as BLI-BRT, LCI improves SESCC visibility compared with WLI. This is useful for cases with multiple LVLs. In cases without background coloration (BGC), LCI may make SESCC more visible than BLI-BRT.